Galileo Galilei (1564-1642). 1891 illustration of the Italian physicist, mathematician, astronomer and philosopher Galileo Galilei looking through a telescope. Galileo played a major role in the scientific revolution. His achievements include improvements to the telescope and consequent astronomical observations, and support for Copernicanism. Galileo has been called the father of modern observational astronomy, the father of modern physics, the father of science and the father of modern science.